Nickel Salicided Source/Drain Extensions for Performance Improvement in Ultrascaled (Sub 10 nm) Si-Nanowire Transistors

Abstract

This letter demonstrates successful integration of Gate-All-Around (GAA) nanowire (NW) transistors with low-resistivity metallic NW point contacts at source/drain extensions. Ultrascaled GAA silicon NW transistors with gate lengths down to 8 nm have been achieved, exhibiting good performance among the NW FETs reported to date. Compared to the reference devices, the metallic contact NW devices show 580% enhancement in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> from 103 to 705 muA/mum , at a fixed <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> of 10 nA/mum . Nickel silicide resistivity for ultrathin films is also investigated in this letter for the integration of salicided source/drain extensions with the GAA NW process. Experimental results show that 4 nm of deposited Ni is suitable for forming NW contacts with 10-nm diameters, which is thin enough to avoid oversilicidation while meeting the low-resistivity requirements.